The Research Ofultra-micro Electrode Machining Technology

Micro electrochemical machining technology is one of the important specialprocessing technology,which has been used to process varieties of small parts according tothe principle of metal’s anodicdissolves(cathode precipitate) in the electrolyte. Because ofits irreplaceableadvantages, such as no machining deformation and stress, no tools cathodeconsumption, high productivity and so on, micro electrochemical machining technologyhas been widly payed much attention by many scholars in the world and occupies animportant position in the micro-special-machining technology.The cathode is an importantpart of the micro electrochemical machining technology. Its scale determines the accuracyof micro-electrochemical machiningtechnology.Therefore researching thepreparationofmicro-electrodes means great significance.The author has done some related researchesabout the technology inthis paper. Contents of the study are listed as follow:The formation mechanism of electric double layer and electrode process is analyzed.The equivalent circuit model of electrochemical preparation of the micro-electrode isestablished as well. The relationship equation of the resistance’s increment and electrode’radius is deduced. The regular pattern of the electric current in steady-state electrodeprocess is achieved. The derived formula is provedcorrectly by comparingthe theoreticalcalculations of current withthe experimental values.The cylindrical micro-electrodes are produced bymaking use of the method based onthe machining principle of electrochemical etching, by which the important experimentalparameters such as voltage, current, processing time, the concentration of the electrolyteetcwereobtained. By comparing two groups of the different experiments,the regularpatterns wereobtained，which shows effects of current and processing time on theelectrode’s shape and diameterin the conditions of different machining voltage anddifferent concentration of electrolyte. By improving the structure of the cathode,anultra-micro-electrode with a diameter of1μm, length of8μmwere prepared by using theparameters obtained in the experiments.According to the experimental characteristics of ultra-micro electrodes, an equipment which can detect ultra-weak current thereby controlling experiments’ processesisdesigned.It improvedthe success rate of ultra-micro electrodemachining.Experiments on fabrication of microporeat the stainless steel by micro electrolysisforming machine with produced uniform cylindrical micro-electrode are carried out.Effects of machining voltage, concentration of electrolyte and feed rate on the micromachining accuracy are investigated.The researches show that the machining accuracy ofmicropores can be improved with taking low concentrations of the electrolyte,smallmachining voltage and lowfeed speed.